Tuesday, May 12, 2015

Strasburg's Release Point - 2015 Edition

During the offseason, we noticed that Stephen Strasburg moved over on the rubber to his pitching arm side by about a foot. He made the change during July of last season, and has stuck with it through his starts this season as you can see in the chart below:

What the chart shows is the relative vertical release point (y-axis) and horizontal release point (x-axis). The cluster on the right around the measurements (-1.5, 6) is his release point during the first 7 months of 2014. You see a pretty tightly clustered collection of bubbles. That in itself is a positive as it means Strasburg was doing a good job of repeating his delivery. The cluster on the left around (-2.5, 6) are his release points starting August of 2014 through today. As we noted in the post during the offseason, Strasburg has not altered his delivery, but rather has shifted over on the rubber by about a foot, for good it seems.

Interestingly, the little collection of bubbles in between the two big clusters are from his most recent start against the Marlins, the start in which he left early after shoulder something-or-other that may have been a cramp or a result of a gimpy ankle or because he drove over speed bumps too fast? Whatever the root cause, it did have an impact on his release point as we can see in the graph.

One theory I had was that Strasburg shifted over on the mound to change how hitters pick up on his delivery. Generally, a move to his pitching hand side would make it harder for right handed hitters to pick up the ball. It’s not like Strasburg had struggled against right handed hitters, though. In 2013 and 2012 (Strasburg’s release point in those years mirror his 2014 release point pre-shift on the rubber), Strasburg allowed only a .249 wOBA and .255 wOBA respectively to right handed hitters while left handed hitters hit over 40 points higher each year. That quick analysis doesn’t suggest a move was necessary due to struggles against righties.

Strangely enough, through the small sample size of the 2015 season so far, right handed hitters have actually hit better against Strasburg than left handed hitters. If the goal was to better attack right handed hitters, it’s not working.

Clearly, there are a multitude of reasons why Strasburg might have shifted over on the rubber, outside of attacking right handed hitters. He could be looking for a more consistent landing point or he could be using it to help control the running game better (something he has admitted to working on in the past). This kind of change isn’t something that a major league pitcher does unknowingly or without thought, so I would be interested to see what Strasburg has to say about it now that we can conclude it is a change that’s here to stay.

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